Ionic currents in the sensory epithelium examined in isolated electroreceptors of Plotosus under simulated in situ conditions.

The hypothesis of steady epithelial current in an electrically biased sensory epithelium was examined in Plotosus electroreceptors. The in situ conditions were simulated reversibly by electronic shunting of isolated receptors. The epithelial current had an N-shaped property due to Ca current superimposed over passive bias current, with net current close to zero when unstimulated. The high-gain synaptic transfer proved to be the result of modulation of steady Ca component.